Closures such as crown seals or caps are routinely used and are well known in the art for sealing the openings of containers or bottles which typically contain carbonated or other beverages. With respect to crown seals, they are commonly formed of metal sheet material and comprise a top, a sidewall with a flared skirt. The skirt includes a plurality of flutes which extend around the circumference thereof at spaced intervals. When applied to cover an open end of a bottle, these flutes are bent or crimped at the points of intersection between the top and the skirt, gripping a bead at the upper rim of the bottle opening for sealing.
In recent years "twist-off" crown seals have become more popular and are used by beverage manufacturers. The twist-off crown seals are convenient and preferred by consumers because they can be removed from bottles without the use of bottle openers. The twist-off crown seal includes internal threads which engage corresponding external threads on the container or bottle. The twist-off crown seal is removed by rotating the crown seal to unthread the crown seal from the bottle.
To obtain a seal of sufficient strength which will withstand the pressure of the contained carbonated or other beverages, a metal such as steel is typically used to form the crown seal. The metal flutes are relatively sharp, however, and can be injurious when grasped by a consumer when the bottle is picked up or opened. Particularly with the twist-off crown seal design, the sharp edges of the flutes can be painful and dangerous as the crown seal is removed.
With respect to tamper evidence, moreover, crown seals, particularly twist-off crown seals, can easily be replaced onto the bottles after being removed with little or no evidence that the bottles have been opened or tampered with. Thus, crown seals for bottles are beset with drawbacks and problems associated with their removal and replacement in opening and closing containers, such as bottles.